Fences having intersecting vertical pickets and horizontal rails have recently become popular and are strong, durable and attractive, while requiring little or no maintenance. In most fence designs, fences use fasteners, such as screws, to fix a plurality of horizontal rails to a plurality of vertical pickets. A disadvantage to these designs that use fasteners is that the fasteners often rust and corrode. Further, it is difficult to assemble fences using screws, as it is hard to tighten the screws in the rails to attach the rails to vertical pickets. Moreover, if screws are used, then the fence cannot rotate, thus, making it difficult to set the fences on uneven surfaces.
There are various designs for fences having vertical pickets and horizontal rails known in the prior art. U.S. Pat. No. 7,384,025 to Lo, U.S. Pat. No. 7,347,412 to Zhu and U.S. Pat. No. 6,173,944 to McCarthy all have screws engaging the coupling bars. While the screws are hidden in these designs, these designs suffer from having the screws rust and corrode, and these fence designs are difficult to assemble.
U.S. Pat. No. 5,454,548 to Moore is a fence design having a solid coupling bar with locking means that firmly locks the rails into pickets forming a rigid structure and thus not enabling any rotation of the rails with the pickets or posts. U.S. Pat. No. 6,375,166 to Schall et al. uses inserts with legs for attachment; U.S. Pat. No. D479,612 to Larsen et al. and U.S. Pat. No. 6,969,051 to Gibbs use a locking rod; U.S. Pat. No. 7,021,607 to Alexander uses clips having flaps for attachment; and U.S. Pat. No. 6,752,386 to Bundy uses a sliding lockbar for attachments to a fence assembly.
A screwless retaining bar for a fence assembly is disclosed in U.S. Patent Publication No. 2013/0264532, which is hereby incorporated by reference in its entirety. The retaining element allows the vertical pickets of the fence to rotate with respect to the horizontal rails of the fence so that the fence can be installed on an uneven surface.